With the right trainer and the right equipment, it only takes about seven and a half hours of hard work and conditioning. Push ups will definitely help.
The actual action of doing a back handspring only takes about 4 seconds. But, if you mean learning to do a back handspring, that time can vary depending on the person and the time spent practicing....
Honey, it completely depends on the person. It took me to learn it in 9 days (5 practices) to learn it. If you are at the stage, and you have the skills in order for it to work, you'll get it in no...
This depends greatly upon how flexible you are and how often/hard you work at it. You could easily learn how to do so with proper exercise and spotting in a week or two but if you are a good ways...